package com.ks.utils;

import java.security.SecureRandom;
import java.util.UUID;

/**
 * 封装各种生成唯一性ID算法的工具类.
 * 
 */
public class Identities {

	private static SecureRandom random = new SecureRandom();

	/**
	 * 封装JDK自带的UUID, 通过Random数字生成, 中间有-分割.
	 */
	public static String uuid() {
		return UUID.randomUUID().toString();
	}

	/**
	 * 封装JDK自带的UUID, 通过Random数字生成, 中间无-分割.
	 */
	public static String uuid2() {
		return UUID.randomUUID().toString().replaceAll("-", "");
	}

	/**
	 * 使用SecureRandom随机生成Long.
	 */
	public static long randomLong() {
		return Math.abs(random.nextLong());
	}
	
	/**
	 * 唯一长整整
	 * @return
	 */
	public static long unionRandomLong() {
		synchronized (new Object()) {
			return Math.abs(
//					(((long) (randomLong() & 0xFFFF)) << 48)
//					|
					(((randomLong()+System.currentTimeMillis() ) & 0x00000000FFFFFFFFl) << 16) 
//					|
//					randomLong()+System.currentTimeMillis() 
					);
		}
	}
	
	public static void main(String[] args) {
		for (int i = 0; i < 10; i++) {
			System.out.println(Identities.unionRandomLong());
		}
	}

}
